Droplet Evaporation of Pure Water and Protein Solution on Nanostructured Superhydrophobic Surfaces of Varying Heights

Langmuir ◽  
2009 ◽  
Vol 25 (13) ◽  
pp. 7561-7567 ◽  
Author(s):  
Chang-Hwan Choi ◽  
Chang-Jin “CJ” Kim
Keyword(s):  
Pure Water ◽  
Droplet Evaporation ◽  
Superhydrophobic Surfaces ◽  
Protein Solution

Evaporative Particle Deposition on Superhydrophobic Surfaces

2013 ◽  
Author(s):  
Mercy Dicuangco ◽  
Susmita Dash ◽  
Justin A. Weibel ◽  
Suresh V. Garimella
Keyword(s):  
Contact Angle ◽  
Particle Deposition ◽  
Contact Angle Hysteresis ◽  
Droplet Evaporation ◽  
Superhydrophobic Surfaces ◽  
Contact Radius ◽  
Droplet Shape ◽  
Substrate Heating ◽  
Solid Liquid ◽  
Constant Contact Angle

The ability to control the size, shape, and location of particulate deposits is important in patterning, nanowire growth, sorting biological samples, and many other industrial and scientific applications. It is therefore of interest to understand the fundamentals of particle deposition via droplet evaporation. In the present study, we experimentally probe the assembly of particles on superhydrophobic surfaces by the evaporation of sessile water droplets containing suspended latex particles. Superhydrophobic surfaces are known to result in a significant decrease in the solid-liquid contact area of a droplet placed on such a substrate, thereby increasing the droplet contact angle and reducing the contact angle hysteresis. We conduct experiments on superhydrophobic surfaces of different geometric parameters that are maintained at different surface temperatures. The transient droplet shape and wetting behavior during evaporation are analyzed as a function of substrate temperature as well as surface morphology. During the evaporation process, the droplet exhibits a constant contact radius mode, a constant contact angle mode, or a mixed mode in which the contact angle and contact radius change simultaneously. The evaporation time of a droplet can be significantly reduced with substrate heating as compared to room-temperature evaporation. To describe the spatial distribution of the particle residues left on the surfaces, qualitative and quantitative evaluations of the deposits are presented. The results show that droplet evaporation on superhydrophobic surfaces, driven by mass diffusion under isothermal conditions or by substrate heating, suppresses particle deposition at the contact line. This preempts the so-called coffee-ring and allows active control of the location of particle deposition.

Inhibition of Blockage by Ice Crystal in Water in a Micro-Channel by Using Antifreeze Protein

2010 ◽  
Author(s):  
Yoshimichi Hagiwara ◽  
Yosuke Ohnishi ◽  
Daichi Yamamoto
Keyword(s):  
Flow Rate ◽  
Pure Water ◽  
Antifreeze Protein ◽  
The Other ◽  
Micro Channel ◽  
Ice Crystal ◽  
Protein Solution ◽  
Local Cooling ◽  
Solution Flow ◽  
Temperature Changes

Experiments have been conducted into the freezing of water flow and the aqueous solution flow of winter flounder antifreeze protein in a micro-channel of 0.15mm in height, 1.2mm in width and 21mm in length. The local temperature is measured with a sheathed thermocouple of 0.1mm in diameter. Nearly flat interfaces, parallel to the cooling sidewall of the channel, are observed in the case of pure water regardless of flow rate. On the other hand, serrated interfaces are observed in the case of protein solution flow regardless of flow rate. The decreasing rate of the temperature changes when the interface reaches the thermocouple. Around this instant, a slight increase in the temperature is observed due to supercooling release. In the case of local cooling, the interface becomes more serrated as the flow rate increases. This is because the interaction between the interface and the protein continuously approaching the interface due to the flow occurs more frequently with an increase in the flow rate.

Effects of Surface Topography and Colloid Particles on the Evaporation Kinetics of Sessile Droplets on Superhydrophobic Surfaces

2012 ◽  
Vol 134 (5) ◽  
Author(s):  
Wei Xu ◽  
Chang-Hwan Choi
Keyword(s):  
Rate Constants ◽  
Water Droplet ◽  
Evaporation Rate ◽  
Pure Water ◽  
Hydrophobic Surface ◽  
Superhydrophobic Surfaces ◽  
Clear Correlation ◽  
Planar Surface ◽  
Kinetics Of ◽  
Evaporation Kinetics

In this paper, the evaporation kinetics of microliter-sized sessile droplets of gold colloids (∼250 nm in particle diameters) was experimentally studied on micropatterned superhydrophobic surfaces, compared with those of pure water on a planar hydrophobic surface. The structural microtopography of superhydrophobic surfaces was designed to have a constant air fraction (∼0.8) but varying array patterns including pillars, lines, and wells. During evaporation in a room condition, the superhydrophobic surfaces exhibited a stronger pinning effect than a planar surface, especially in the initial evaporation stage, with significant variations by the surface topographies. Compared to a pure water droplet, colloids exhibited further promoted pinning effects, mainly in the later stage of evaporation. While the well-known evaporative mass transport law of sessile droplets (i.e., linear law of “V2/3∝t”) was generally applicable to the superhydrophobic surfaces, much smaller evaporation rate constants were measured on the patterned superhydrophobic surfaces than on a planar hydrophobic surface. A colloidal droplet further showed lower evaporation rate constants than a pure water droplet as the concentration of particles in the droplets increased over the evaporation. Such transition was more dramatic on a planar surface than on the micropatterned surfaces. Whereas there was no clear correlation between evaporation mode and the evaporation rate observed on the superhydrophobic surfaces, the prominent decrease of the evaporation rate on the planar hydrophobic surface was accompanied with the onset of a second pinning mode.

scholarly journals Measurement of Water Mole Fraction from Acoustically Levitated Pure Water and Protein Water Solution Droplets via Tunable Diode Laser Absorption Spectroscopy (TDLAS) at 1.37 µm

2021 ◽  
Vol 11 (11) ◽  
pp. 5036
Author(s):  
Julian F. A. Perlitz ◽  
Heiko Broß ◽  
Stefan Will
Keyword(s):  
Critical Point ◽  
Diode Laser ◽  
Pure Water ◽  
Tunable Diode Laser ◽  
Acoustic Levitation ◽  
Formation Processes ◽  
Drying Process ◽  
Protein Solution ◽  
Laser Absorption ◽  
Diode Laser Absorption

In order to understand the evaporation and particle formation processes of sprays in technical applications such as fuel injectors or drying processes in the food and pharmaceutical industries in detail, single droplet drying experiments, for example, acoustic levitation, are widely used as model experiments. We combined acoustic levitation and tunable diode laser absorption spectroscopy (TDLAS) to measure the absolute H2O concentration in the exhaust gas of a levitation chamber to investigate drying and particle formation processes from single droplets of pure water and protein–water solutions. To that end, we designed and developed a non-invasive, calibration-free TDLAS-based hygrometer to analyze the 1.4 µm overtone band. To increase the detection range of the developed hygrometer and to track the complete drying process of protein solution droplets even after the critical point of drying, the absorption length was extended to a path length of 18 m using an astigmatic multipass cell of the Herriott type. The setup was validated by drying pure water droplets, resulting in a determination of the water mole fraction in a range from 73 ppm to 1314 ppm, with a single scan resolution of 1.7 ppm. For protein solution droplets, the entire drying process, even beyond the critical point of drying, can be tracked and the different phases of the drying process can be characterized at different drying temperatures.

Local Temperature and Heat Flux in the Aqueous Solution of Antifreeze Protein Near Ice Surfaces in a Narrow Space

2010 ◽  
Author(s):  
Yoshimichi Hagiwara ◽  
Daichi Yamamoto ◽  
Yosuke Ohnishi
Keyword(s):  
Aqueous Solution ◽  
Heat Flux ◽  
Near Infrared ◽  
Pure Water ◽  
Infrared Camera ◽  
Interface Velocity ◽  
Antifreeze Protein ◽  
Heat Of Fusion ◽  
Protein Solution ◽  
The Difference

Experiments have been conducted into the unidirectional freezing of an aqueous solution of winter flounder antifreeze protein 0.02mm thick. It is confirmed that the instantaneous temperature field can be measured with a near-infrared camera. It is found that the difference between the conduction heat flux of pure water near the interface and that of ice is approximately equal to the heat flux for solidification, which is the product of ice density, interface velocity and the latent heat of fusion. The sum of the conduction heat flux of protein solution near the front edge of the serrated interface and the heat flux for solidification is approximately equal to the conduction heat flux of ice. On the other hand, the sum of the conduction heat flux of protein solution near the bottom edge of the serrated interface and the heat flux for solidification is much higher than the conduction heat flux of ice.

Water droplet evaporation from sticky superhydrophobic surfaces

2017 ◽  
Vol 111 (2) ◽  
pp. 021603 ◽  
Author(s):  
Moonchan Lee ◽  
Wuseok Kim ◽  
Sanghee Lee ◽  
Seunghyeon Baek ◽  
Kijung Yong ◽  
...  
Keyword(s):  
Water Droplet ◽  
Droplet Evaporation ◽  
Superhydrophobic Surfaces

scholarly journals Flow Visualization During Droplet Evaporation on Hydrophobic and Superhydrophobic Surfaces

2014 ◽  
Vol 136 (8) ◽  
Author(s):  
Susmita Dash ◽  
Aditya Chandramohan ◽  
Suresh V. Garimella
Keyword(s):  
Flow Visualization ◽  
Droplet Evaporation ◽  
Superhydrophobic Surfaces

Photogallery Entry 17

scholarly journals THE RHEOLOGY OF THE BLOOD. V

1945 ◽  
Vol 28 (6) ◽  
pp. 605-626 ◽  
Author(s):  
Eugene C. Bingham
Keyword(s):  
Singular Point ◽  
Serum Albumin ◽  
Simple Formula ◽  
Volume Concentration ◽  
Pure Water ◽  
Great Majority ◽  
Close Packing ◽  
Protein Solution ◽  
Egg Albumin ◽  
Concentration Curves

A study has been made of those proteins which might offer exceptions to the law that the fluidity of a protein solution is a linear function of the volume concentration; viz., egg albumin, serum albumin, pseudoglobulin, euglobulin, gelatin, and sodium caseinogenate. Solutions of egg albumin below 20 per cent by weight obey the above law but somewhat below 30 per cent the fluidities begin to be too high, presumably due to the contribution to the fluidity made by the deformation of the particles as they come into contact, as the fluidity approaches zero. The fluidity of serum albumin solutions shows a similar behavior, being exceptional above 15 per cent in weight. Pseudoglobulin and euglobulin give fluidity-concentration curves (Fig. 4) which are linear up to about 2.5 per cent each in a total range of 20 and 14 per cent respectively. From this singular point both compounds show a second range which is linear. Pseudoglobulin is the only substance whose solutions seem to show a third linear range. We have also used the data of Chick and Martin for sodium caseinogenate and found evidence for two linear régimes. It is desirable at this time to call attention to the measurements of the flow of glycogen solutions by Botazzi and d'Errico (14) which in Fluidity and See PDF for Structure plasticity, page 207, are expressed in rhes. The data show two linear fluidity curves of different slopes. In this case it was definitely known that the data for each curve were measured with different viscometers which suggested the possibility of an error in viscometry entering in to confuse the issue. We have no suspicions as to the reliability of the data studied in this paper; we only wish to caution the readers that our hypotheses based on these data must be regarded with due reserve until confirmed. We have found a formula (11) based on the supposed linear relation between logarithmic fluidities and concentration which is convenient to use within the range, but close examination reveals that it does not reproduce the data for the higher concentrations at 25° nor does it permit extrapolation to pure water It is not realistic enough because it does not contemplate any change of régime in going from viscous to non-Newtonian or plastic flow. The formula does not apply to any other of the proteins studied in this paper nor to the great majority of proteins already reported as following the linear law. These are serious objections. We have therefore offered as an alternative a simple formula (24) according to which the fluidities are additive in the viscous régime. When the emulsoid particles approach close packing, they are deformed and this deformation contributes to the flow and the fluidity volume concentration curve is again linear. In fact, there may be one or more additional changes of régime.

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